Topic 1 has two halves: 1.1 Systems in organisations — how new IT systems are planned, analysed, built and introduced — and 1.2 System design basics — the components, stakeholders and control aspects of a computer system.
Work through each screen, answer the questions as you go (some are wordy, some are calculations) and collect ⭐ stars. Press Start when you are ready.
SDLC
The software development life cycle
New systems are built through a structured software development life cycle (SDLC). The main stages are:
Analysis — investigate the current system and gather requirements.
Design — plan data structures, interfaces, processing and outputs.
Implementation — write and configure the software.
Testing — check the system behaves correctly.
Maintenance — fix faults and adapt to new needs.
Prototyping builds a scaled-down working model early so users can give feedback before the full system is committed.
Requirements
Gathering requirements
During analysis, the systems analyst studies the existing system and elicits requirements from stakeholders using several methods:
Observation — watch the current workflow directly (accurate, but people may act differently when watched).
Interviews — deep, flexible questioning of individuals.
Questionnaires — reach many people quickly and cheaply.
Collecting documents — study existing forms, reports and records.
Quick check
Choosing a method
?You need typical facts and figures from a large workforce spread over many sites, quickly and cheaply. Which requirements-gathering method fits best?
Changeover
Introducing the new system
When the finished system replaces the old one, the organisation chooses a changeover (conversion) method, trading off risk against cost:
Direct (big-bang) — old off, new on. Cheapest but highest risk.
Parallel running — both run together and outputs are compared. Safe but expensive (double work).
Phased — introduced one module at a time.
Pilot — trialled in one branch or department first.
Match it
Match the changeover method
Tap a description on the left, then the changeover method it describes on the right.
Description
Method
Migration
Data migration and legacy systems
Moving data from an old (legacy) system into a new one is data migration. It often fails or loses data because of:
Incompatible file formats and different data structures.
Different character sets, date or currency conventions across countries.
Incomplete or inconsistent records in the old data.
Different naming conventions and validation rules.
Quick check
Why migration fails
?A company merges two systems built in different countries. Records will not import correctly. Which is the most likely technical cause?
Testing
Testing and debugging
Testing checks the system with carefully chosen data:
Normal data — typical, valid values.
Boundary (extreme) data — values right at the edge of what is allowed.
Abnormal (erroneous) data — invalid values that should be rejected.
Alpha testing is done in-house; beta testing is done by selected outside users; user acceptance testing confirms the system meets the client requirements.
Quick check
Test data
?A field accepts ages from 0 to 120. Which value is a boundary test?
Software — system software (operating system) and application software.
Peripherals — devices attached for input and output.
Networks — the connections that let systems communicate.
Human resources — the people (analysts, users, trainers, managers).
Sort it
Hardware, software or people?
Tap an item, then tap the category it belongs to.
🖥️ Hardware
💾 Software
👥 Human resource
Control
System design and control
A control system follows the input to process to output pattern and often uses feedback. Designers must also consider usability (ergonomics, accessibility) and the social and ethical impact: reliability, safety, and the consequences of failure.
Usability means the system is effective, efficient and satisfying for real users — clear interfaces, sensible error messages and accessibility for people with disabilities.
Quick check
Safest changeover
?A hospital patient-records system must not lose data during changeover, whatever the cost. Which method is safest?
Reliability
Backup, recovery and failover
Organisations protect data and continuity with:
Regular backups — full and incremental copies kept off-site.
Redundancy and failover — duplicate hardware that takes over automatically.
A disaster recovery plan — documented steps to restore service after failure.
Quick check
Why back up
?Why should critical business data be backed up regularly and stored off-site?
Usability
Usability and accessibility
A good system is usable: effective, efficient and satisfying to use. Designers consider ergonomics, clear layouts and helpful error messages, and accessibility so people with disabilities can use it (screen readers, high contrast, keyboard control).
Quick check
Accessibility
?Adding screen-reader support and high-contrast text to a system mainly improves its:
Recap
The big ideas to know
SDLC: analysis to design to implementation to testing to maintenance